The twig concept is a good idea. I passed on a shot at a great buck this year because the light was fading even though I would have still been legal. The next day I sat in the same stand and when it got light I could see some twigs that could have easily deflected my shot. I was sure glad I passed. Game laws are there for a good reason, I guess, not just some arbitrary idea. We have a half hour before and after sunrise/sunset here but that's pretty liberal. Last year, I shot my buck at 7:30 a.m. Sunrise was at 7:15 a.m. I was 45 minutes into legal shooting hours, but it was still pretty dim. I sure wouldn't have attempted the same shot 45 minutes earlier.
I like to get to my stand well before daylight, and if there are deer around, I stay until well after dark. I still won't shoot until there is plenty of light. I find the older I get, the more light I need.